Folding systems usually include a folding blade cylinder and a folding flap cylinder, which has folding flaps in which projectable folding blades from the folding blade cylinder can engage. Some of the folding blade cylinders also have puncture needles to hold sheet products on the folding blade cylinder and carries the sheet products around the folding blade cylinders.
For some operations, it is desirable to change the mode of operation of the folding blade--folding flap cylinder combination to accumulate a number of sheets on the folding blade cylinder before the folding blades are projected, so that a number of sheets can be folded at the same time.
A printing machine having a combination collection and folding blade cylinder is available commercially under the Registered Trademark "LITHOMAN", made by MAN-Roland Druckmaschinen AG, Offenbach, Fed. Rep. Germany, and distributed in the United States by M.A.N. Roland USA, Inc., of Middlesex, N.J. Change-over between the respective operating modes--folding and either assembling or collecting--is done when the machine is stopped. A bolt couping is engageable with fitting holes. A hand wheel is engageable with the main drive of the cylinder and, by rotating the hand wheel and selectively engaging the bolt coupling in the respective holes, a covering cam disk for the operating cams of the folding blades as well as a needle covering cam disk for the puncturing needles is angularly or circumferentially shifted with respect to a fixed cam disk for the folding blades and the puncturing needles. Engagement of the coupling bolts requires careful rotation of the hand wheel to ensure alignment of the coupling bolts with the respective fitting engagement holes. Change-over is possible only manually.